Printer cartridges are typically designed to provide the consumer a certain number of print copies before the toner or ink is exhausted. The total number of prints varies depending on the type, quality and density of the print provided by the printer. After all of the toner or ink is spent, the cartridges are either thrown away or recycled.
An emerging industry has developed that deals with the recycling of printer cartridges. Typically, the cartridge is recycled by a cartridge remanufacturer, who receives spent printer cartridges and refurbishes them. The refurbishment process entails replacing the worn or nonfunctioning parts, refilling the cartridge with either toner or ink, and distributing the refurbished cartridges into the marketplace.
Toner cartridges are typically designed to fit into one type of laser printer or family of laser printers. For example, the same toner cartridge may be used in an HP4200 or HP4300 monochrome laser printer. As new printer models are introduced, the printer manufacturer may decide to alter the physical characteristics of the printer cartridge. In some cases the alteration may be an entirely new shape or the printer manufacturer may only change a minor detail such as an indentation or a protrusion on the cartridge.
Additionally, different toner cartridges may be used within the same printer. These toner cartridges may have very similar physical characteristics. For example, in the HP2500 color laser printer, there are four separate toner cartridges containing black and colored toner (magenta, cyan, and yellow). The physical differences between the toner cartridges for the HP2500 color laser printer are relatively minor. The HP2500 cartridge manufacturer has installed a protrusion in a unique location on one of the ends of each toner cartridge to distinguish each toner cartridge from one another. The protrusion mates with a corresponding recess in the printer's toner cartridge space. When the cartridge is inserted into the printer, the protrusion aligns with the recess allowing only the designated cartridge to be installed.
A typical toner cartridge comprises an assembled plastic housing. The material of the housing may be molded plastic or other plastic composite. During the remanufacturing of the cartridge, the cartridge is disassembled, cleaned, refurbished and reassembled. The last step of the refurbishment process includes refilling the cartridge with toner and the cartridge is repackaged. As part of the refurbishment process, the toner cartridges may be modified in order to remove any restriction regarding usage.
Additionally, some printers separate the toner storage function from the image transfer function. In these printers, toner is stored in the toner cartridge and an imaging drum unit performs the imaging function. In some printers, the imaging drum unit may be a field replaceable unit. Typically within the imaging drum unit is the OPC (Organic Photo Conductor) drum as well as the various image transfer components. The imaging drum unit may also have certain physical characteristics unique to a particular printer model type or family. For example, the imaging drum unit for the HP2500 and HP2550 may be identical except for a protrusion or recess located on the endplates of the unit.
The present invention is intended for use in removing a protrusion on an end plate of a toner cartridge to allow the modified toner cartridge to be used in different locations within the same printer or other printers. Another embodiment of the present invention is designed to alter the physical characteristics of an imaging drum unit to allow the modified imaging drum unit to be used in other printers.